How does population density affects the health condition in Japan ?

Population affects japan's healths in many ways Automobile accidents are more likely to occur in the streets

disease spread much quickly than normal because of too many trash and pollution but japan realized the problem so they began to think Globally and now japan has one of the highest life expectancy. Japan to started to recycle and new laws were introduce to dramatically reduce pollution and streets are regularly clean and people now take care and when sick wear mask and protect the people around them